The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A consideration of vehicle driveability is powertrain output and vehicle response to that output. Powertrain output can be referred to as a twisting force known as torque. Torque is the twisting force generated from an internal combustion engine, or other torque source, e.g., electric motor, to propel the vehicle. In the case of an automobile or other vehicle with drive wheels, torque may be transferred through a transmission, split by a differential, and provided to wheels to provide tractive force to the vehicle.
Torque information can be used in a variety of powertrain control schemes, e.g., clutch fill-time detection, engine torque estimation, transmission shift smoothing, etc., which aid in vehicle drivability. Therefore, torque information can be used for added control of the powertrain. For example, during acceleration and deceleration, occupants of a vehicle can detect changes in torque transferred, e.g., during transmission shifts. Control schemes that control the transmission shifting can be utilized to minimize torque disturbances during shifting. A closed-loop control scheme can be used for transmission shifting allowing a control module to estimate the amount of torque being produced in a current transmission gear ratio based on an amount of torque the engine should be producing at a given RPM level. However, this is a theoretical torque and not necessarily representative of the actual torque being transferred. A control scheme can be devised for engine and transmission control based on a dedicated torque sensor. Dedicated torque sensors are able to detect an actual amount of torque being transferred and provide the actual torque information to the control module for determining a transmission shift scheme based on current conditions. However, dedicated torque sensors for use in production vehicles increase cost, part content, wiring harness complexity, mass and reliability issues.